Because of the environment in which exhaust gas recirculation valves normally operate, they are highly susceptible to carbon buildup resulting in malfunction. Heretofore valves of this general type were not readily capable of being at least partially disassembled for cleaning and, thus, in lieu of cleaning it became customary to replace the entire valve, thereby significantly increasing maintenance costs.
In most present day vehicles there are severe limitations in the space provided under the hood to accommodate the engine and the various accessory components associated therewith. As a result of this condition, it is necessary that the vacuum tube connected to a section of the valve housing be placed in a precise location so as not to interfere with any parts or components of the engine. As a result of such space limitations, the precise locating of the valve within the space, and the variation in the size and location of the vacuum tube connected to the valve, a proliferation of modified versions of the valve, commonly referred to as an EGR valve, has resulted even though the flow specifications and operating characteristics thereof are the same. Thus, an auto or truck mechanic is required to maintain a substantial inventory of the various valves so that repair and maintenance of the engine can be expeditiously performed. The cost of maintaining such an inventory and of obsolescence of such valve inventory due to changes in styling and size of the vehicle engine and body oftentimes imposes a severe financial burden on the mechanic or his employer.